Dietary Supplement. Natural Mediterranean tree resin. Protects the stomach and duodenum. Mastic Gum 500 contains natural tree stem mastic gum (Pistacia lentiscus) from a shrub-like tree grown mainly in Greece and Turkey. Mostly composed of resinous gum and volatile oils, mastic has been used for centuries by traditional healers for stomach distress. Mastic Gum protects gastric and duodenal cells and tissues. No wheat, no gluten, no soybeans, no dairy, no egg, no fish/shellfish, no peanuts/tree nuts. (These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.)